1. Technical Field
The disclosure relates generally to a turning knob control device, and more particularly to a turning knob control device for controlling a touch panel.
2. Related Art
The integration of the touch panel or the touch pad has become the trend because the user interface on portable information technology (IT) products can be more user friendly. Panel manufacturers and integrated circuit (IC) design companies have made touch panel technologies their main research topic, and related techniques and products have been applied in electronic products of everyday life, as in IT products such as mobile phones, computers, and personal digital assistants (PDAs).
The touch devices commonly adopted nowadays are mainly categorized as resistive and capacitive, in which the main operating principle of the capacitive touch devices relies on sensing the electrical characteristics of a capacitance. When two layers of electrically conductive objects approach each other but do not touch, the electric fields act to generate a capacitance. The upper and lower layers in a touch panel structure are conductive layers respectively formed by electrical traces arranged in interlaced directions. A finger is also an electrically conductive object. When the finger is placed on the touch panel, a extremely small capacitance is formed between the electrical traces of the touch panel and the finger. A microprocessor can detect the touch position of the user by using the capacitance variation.